Diamond Electronics… In Space
Diamonds, beyond their notorious rarity and allure as jewellery, may soon form the heart of the electronic systems that will enable next generation satellite communications and deep space exploration missions.
In the harsh environments of space, both mechanical and electrical systems must withstand bombardment from radiation and exposure to a wide range of temperatures from well below freezing to hundreds of degrees centigrade. Engineers then face the challenge of designing systems that must operate reliably in such uniquely hostile conditions. Isolated in the depths of space, even the most minor of system failures can lead to not only the loss of millions of pounds of investment, but also potentially the loss of human life. Overcoming these technological challenges remains the key to the continued exploration of space and the development of crucial future satellite technologies. Only through the identification and investigation of new and robust material systems will such challenges be addressed and the associated benefits to mankind come to fruition.
For the development of space-based electronic systems, diamond is truly an ideal material system. The key to diamond’s potential success lies at the heart of its amazing and unique physical properties. Many people are aware of the extreme physical hardness of diamond, but fewer are aware of its electrical properties which are equally remarkable. For example, diamond possesses the highest thermal conductivity of any known solid, which allows heat to flow through it more easily than any other material. It is also extremely robust electrically, which means it can tolerate the high voltages used in spacecraft better than other more commonplace electronic materials such as silicon. Its unique electronic structure means it is also less sensitive to radiation and hence more robust in radiation intensive environments. Electronic charge can also move very fast in diamond, making it ideal for very high frequency applications and high data transfer rates.
Success in the implementation of diamond-based electronics relies heavily on the ability to make a diamond-based transistor, as the transistor remains a key electronic component in modern day electronics. Pioneering work in this area is currently underway at the University of Glasgow in a bid to unlock the revolutionary potential of this material system. Instead of relying on rare, expensive and varied quality diamond mined from the earth’s crust, the availability of synthetic high-quality diamond has now made this research possible. To fully maximise the performance of the diamond transistors, their physical size must be reduced to nano-scale dimensions. This challenging feat is accomplished using the unique capabilities of the James Watt Nanofabrication Centre at the University of Glasgow and the expertise of the Nano-Electronic Diamond Devices and Systems group led by David Moran. Recent progress by this team has resulted in the demonstration of the world’s smallest and fastest diamond transistor with a feature size of 50nm, or approximately 250 carbon atoms in length.
Taming the extreme properties of the diamond material system for inclusion in actual space-based electronic systems remains a challenging task. Success in bringing this technology to maturity however would lead to future satellite communications for higher data transfer rates and digital media distribution, greater supply of high speed broadband to rural areas and next generation ultra-accurate GPS tracking to name but a few. Diamond electronics may also form part of vital systems to allow manned space exploration missions to other planets, moons and other astronomical bodies where potential system failure due to hazardous environments remains one of the main technological hurdles limiting space exploration.
Cutting edge research underway at the University of Glasgow continues to explore the many and varied scientific and technological opportunities that diamond can provide, to push the boundaries of this emerging technology and to bring these exciting possibilities closer to reality.